The present invention relates to a winding machine, and more particularly to such a winding machine which has a winding mandrel immovably retained on a machine frame during winding, and a traversing mechanism.
Winding machines are known for coiling with extremely high yarn speeds, for example 6000 m per minute. In these machines the yarns are reciprocably guided by drivers which are mounted on two oppositely movable band or belt runs. The alternating movement of the yarns is performed here not by a conventional traversing mechanism with a single reciprocably movable yarn guide, but instead by oppositely movable drivers which alternatingly engage and guide the yarns. Since the drivers are neither accelerated nor decelerated at the reversing point of the yarn, the influence of the mass of the yarn guiding elements during the yarn reverse is completely excluded.
With the respective shape of the drivers or relative arrangement of the belt runs, the yarns are released from a driver and simultaneously taken by another driver. The reverse point lies at the location at which the drivers meet. When it is desired to achieve a spool formation with flat and exact end faces, the reverse points must lie exactly at the same locations. Irregular deviations which lie in the dimensions of the thickness of a yarn cause an inaccurate edge formation. A so-called transverse strike takes place, or in other words short yarn pieces run as chords over the edge of the winding. It is therefore necessary to synchronize carefully the movement of the drivers.
Many winding machines are provided with two rotatable belts or bands equipped with drivers. The bands are arranged so that one run of a band is located very close to the run of the other band movable in an opposite direction. In these machines the above mentioned synchronization problems are especially pronounced because partially of a different expansion of the belts or bands as a result of different material properties or because different aging.
Winding machines are also known which include only one rotatable element with opposite runs approaching one another via deviating rollers. While material-caused inaccuracies are excluded here, the above mentioned transverse strike is not completely eliminated. It is also known to arrange fixed diverters at the end of the changing region so that the yarns are always released exactly at the same locations of the incoming drivers.
The above mentioned features are disclosed in the German document DE-OS No. 1,535,091, in which the diverters are arranged differently so that the transversing stroke during the winding process is shortened with increasing coil diameter. The nominal reversing point travels from one coil location to another coil location inwardly when the actual reversing point of one coil location, determined by respective disturbance influence, lies at one side of the nominal reversing point, the yarn nevertheless does not slide from the edge since the position which lies hereinbelow is somewhat wider. The coil obtains conical or curved end surfaces. With a sufficiently great cone angle, the occurrence of transverse strike can be suppressed.
In the winding machine disclosed in the German document DE-OS No. 2,622,243 from which the present invention is initiated, the displacement of the diverters is coupled by a transmission with the position of a sensing element which abuts against the peripheral surface of the coil and deviates in correspondence with the increasing coil diameter. The transmission here includes only a locking gripper-type linkage which must be actuated via a not-described lever device. The exact operation of it is not explained in detail, and it cannot be ascertained whether this device is suitable for winding machines in which a plurality of winding 15 locations arranged in series with one another are associated with a single winding mandrel. This latter consideration is especially important. During winding of thin yarns with extremely high speeds, it is important for avoiding excessive coil weight when up to eight coils are arranged on a winding mandrel.